Positioning receivers typically received weak signals in a pulsed interference environment which use the signals received from GNSS (Global Navigation Satellite System) satellite constellations such as the GPS (Global Positioning System) or enhanced GPS systems, GLONASS (Global Orbiting Navigation Satellite System) and, in the near future, Galileo. The received signal is typically located a few tens of dB below the thermal noise of the receiver. The signal processing needs to allow for the recovery of one or more carriers and one or more modulation codes of said carriers which contain characteristic information on the satellite transmitting said carriers. The central part of the digital processing is a correlation of the received signals with local replicas of said signals. These processing operations presuppose a minimum signal-to-noise ratio at the correlation input of ten or so dBHz. This minimum is not reached in the presence of interference that saturates the receiver to the point of very substantially degrading the useful signal. Such is typically the case with signals used for locating the DME (Distance Measuring Equipment) system relative to notable points on the ground. The ground beacons transmit signals in response to the interrogation signals transmitted by the aircraft. These ground beacons and the onboard interrogators transmit signals of high instantaneous power (of the order of ten or so kilowatts) in the frequency bands used for the positioning signals (in the 1200 MHz region). One known solution to this problem is notably the so-called “blanking” technique which consists in identifying the interfering signal and eliminating the received signal disturbed by the latter from the subsequent processing operations. This solution does not work when the interference density increases to the point of almost permanently covering the useful signal. In this case, the blanking causes any useful signal to be eliminated at the same time as the interfering signal. This type of scenario is likely to occur in a large portion of the European air space, notably at an altitude of around 40 000 feet where the number of DME beacons seen by an aircraft can be of the order of 60 at maximum traffic density times. It is possible, to improve the effectiveness of the blanking, to subdivide the band into several subbands and perform the blanking on each of the subbands which, for given interferences, allows a greater proportion of the useful signal to remain and therefore enhances the signal-to-noise ratio.
However, producing an effective blanking presupposes a servocontrolling of the gain of the receiver on a thermal noise reference, which introduces a loop delay that is prejudicial in cases of rapidly changing interference scenarios.